The climate science behind wildfires: why are they getting worse?

This is a crisis.

If we were on a plane,
I think the pilot's control panel

would have several alarms going off.

Siberia, Usa, Turkey, Greece,
and Italy and Portugal in recent years.

Huge areas just going up in flames.
Everything just being reduced to ash.

Scene after scene of hillsides ablaze.

Wildfires are in one sense very simple.

It just needs a spark
in dry conditions to set them off.

But in another sense
they're also very complex,

because the extent to which they spread

depends very much on
conditions in the ecosystem.

How much moisture is there
in the ground, in the air?

How long has it been
since there was last rainfall?

What kind of trees there are.

How dense is the biodiversity?

Fires tend to burn faster
when they're in a plantation

and there's just one type of tree.

There isn't much undergrowth from moss

and things like that,
that could absorb water.

You get what scientists are always
describing as tinderbox-like conditions,

where it doesn't
take much to start the fire.

and then once the fire is started,
it spreads very very quickly.